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How Facebook Is Saving Power By 10-15% Through Better Load Balancing

Posted by timothy on from the 10-percent-at-web-scale dept.

An anonymous reader writes Facebook today revealed details about Autoscale, a system for power-efficient load balancing that has been rolled out to production clusters in its data centers. The company says it has "demonstrated significant energy savings." For those who don't know, load balancing refers to distributing workloads across multiple computing resources, in this case servers. The goal is to optimize resource use, which can mean different things depending on the task at hand.

8 of 54 comments (clear)

  1. They could save 100% by Anonymous Coward · · Score: 5, Funny

    Just turn it off.

  2. to sum it up by roman_mir · · Score: 3, Informative

    to sum it up, if a FB server is idle it consumes 60 watts, if CPU is minimally utilised it consumes 130 watts and if it's utilised more it consumes 150 watts.

    Instead of round robin use an algorithm that pushes requests to the servers that are already processing other requests, thus allowing many CPUs to remain at 60 watts, while some CPUs to hit 150 watts of power consumption and so instead of doubling or almost trippling power consumption of all servers due to round robin distribution of requests, tripple power consumption of fewer CPUs and let many CPUs to stay at 60 watts.

    Sure, it's an interesting thing to optimise, but unless you are running dozens or maybe hundreds and even thousands of servers in a data centre you won't care about this much at all.

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    1. Re:to sum it up by sociocapitalist · · Score: 2

      to sum it up, if a FB server is idle it consumes 60 watts, if CPU is minimally utilised it consumes 130 watts and if it's utilised more it consumes 150 watts.

      Instead of round robin use an algorithm that pushes requests to the servers that are already processing other requests, thus allowing many CPUs to remain at 60 watts, while some CPUs to hit 150 watts of power consumption and so instead of doubling or almost trippling power consumption of all servers due to round robin distribution of requests, tripple power consumption of fewer CPUs and let many CPUs to stay at 60 watts.

      Sure, it's an interesting thing to optimise, but unless you are running dozens or maybe hundreds and even thousands of servers in a data centre you won't care about this much at all.

      Some of us do actually run hundreds or thousands of web servers so it is actually interesting to us.

      Also, I think the idea is not only applicable to web servers. I'm not an expert in this field but I would think the power consumption difference is due to dynamic frequency scaling both by direct consumption and by subsequent heat generation.

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  3. Switch off servers? by manu0601 · · Score: 2

    TFA is vague on that point: do they switch off some server during idle hours?

    Such a practice seems good for power consumption, but we have to account the fact that switching on and off shortens hardware lifetime: it creates temperature stress, and we all know that electronics most often die at power on time. Hence what looks like a power saving may hide bigger costs (either financial or environmental) for hardware replacement.

    1. Re:Switch off servers? by manu0601 · · Score: 2

      I see the value of having a pool of idle servers ready for request peaks. But the graphs in TFA shows they have huge daily variations, hence it could make sense to switch off a fraction of idle servers.

  4. Should we care? by penguinoid · · Score: 3, Insightful

    Is this a case of "Facebook was being obliviously wasteful" or a case of "Facebook discovers way to increase efficiency"? I'm guessing it's the former.

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    1. Re:Should we care? by penguinoid · · Score: 3, Insightful

      The first is like increasing fuel economy by designing a better engine, the second is like increasing your own fuel economy by patching that leaky fuel tank. Even I know how to turn off or put my computer into sleep mode to save energy -- will anyone but Facebook gain anything from this?

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  5. We all could save energy... by MS · · Score: 2, Funny

    Not only Facebook, but the end-users also could save a lot of electricity by not using Facebook at all. People should get out and have a real social life.